Sodium hydroxide in a solution is a white, odourless, non-volatile solution. It will not burn but it is highly reactive. It can react violently with water and numerous commonly encountered materials, generating enough heat to ignite nearby combustible materials. Contact with many organic and inorganic chemicals may cause fire or explosion. Reaction with metals releases flammable hydrogen gas. Sodium hydroxide in solution is EXTREMELY CORROSIVE. It can cause blindness, permanent scarring and death. Aerosols can cause lung injury and these effects may be delayed.

The main uses of sodium hydroxide are in chemical manufacturing (pH control, acid neutralization, off-gas scrubbing and catalyst); pulp and paper manufacturing; in petroleum and natural gas industry (removing acidic contaminants in oil and gas processing); manufacture of soap and detergents and other cleaning products; and cellulosics, such as rayon, cellophane and cellulose ethers; cotton mercerizing and scouring. Other uses include water treatment, food processing, flue-gas scrubbing, mining, glass making, textile processing, refining vegetable oils, rubber reclamation, metal processing, aluminum processing, metal degreasing, adhesive preparations, paint remover, disinfectant, rubber latex stabilizer and stabilization of sodium hypochlorite.

Sodium hydroxide is produced mainly in three forms: 50% and 73% aqueous solutions, and anhydrous sodium hydroxide in the form of solid cakes, flakes or beads. The major impurities include sodium chloride, sodium carbonate, sodium sulfate, sodium chlorate, potassium and heavy metals such as iron and nickel. This record reviews the information relevant to solutions.

Sodium hydroxide, solutions is also known as caustic soda, liquid caustic (solutions of 45-75% sodium hydroxide in water), lye, soda lye, sodium hydrate, white caustic, and solution d'hydroxyde de sodium.

Its CAS Registry Number sodium hydroxide is 1310-73-2. This number is assigned by the Chemical Abstracts Service (CAS) in the United States and is used as a unique identifier number world-wide.